Missing water tube guide sleeve. Was it there?

[rkilpa]

just completed my 1st water pump impeller replacement on Alpha One Gen 2. Took the route of removing the lower while the upper was still attached to the boat. Removing lower and replacing impeller was pretty straightforward. However, putting the halves back together proved difficult. Part of the problem was getting the water tube lined up with the pump coupling. Finally got it together and tested it. No gear lube leaks, forward and reverse engage and water is exiting through the exhaust outlets so I’m confident the tubes lined up.

Knowing the sleeve is just a guide to make installation easier, I wasn’t too concerned at the time. Afterwards I got to thinking about the missing sleeve. What if it wasn’t missing before I started and fell off when I removed the lower and fell down into the chambers of the housing? My old quad ring fell into the rear chamber and I wasn’t concerned because that’s just the exhaust exit and that little ring should just pass through, right?

But what if the sleeve fell into the same cavity? Since I wasn’t the last one to do this job, I can’t be 100% certain it was there to begin with. Is this something to be concerned about?

 

[harringtondav]

If it didn't fall on the ground it could have fallen down the exhaust passage and may be sitting on top of the propshaft carrier, or wedged in the passage. I don't know if this could cause a big problem. But your thru prop exhaust may be somewhat restricted. Your drive has two exhaust bypass ports at the bottom of the gimbal plate to help with the flow.

Consider dropping the lower hsg and trying to find it in that passage. You can look the carrier if you remove your prop. A replacement is <$8

 

[Rick Stephens]

That part is pretty brittle. They also get more brittle over time as they get heated by exhaust. Would not take much to split one. It almost certainly passes right out the exhaust.

Personally, I recommend you always pull the entire drive when working on it. Takes just a few minutes. Make a simple wooden bench fixture for the lower, like slot cut into a piece of plywood or a couple 2 x 6s side by side to slide the lower into. Then during reassembly you can drop the upper down onto the lower, which is much much easier than trying to lift the lower up without kicking it out of forward gear or damaging the seals. Besides, there are mucho important inspections and greasing needed of u-joints, gimbal bearings and bellows that require annual removal of the upper.

 

[rkilpa]

Consider dropping the lower hsg and trying to find it in that passage. You can look the carrier if you remove your prop. A replacement is <$8

I guess what I'm looking for is reassurance that IF the sleeve did fall into the exhaust passage that it won't damage anything. I really don't want to disassemble and reassemble everything again right away after the difficultly I experienced just to find a piece of plastic that I will have on hand for the next impeller job. IF it's there it can't bind up anything, right?

 

[achris]

It won't damage anything.... It can't bind up anything...

 

[rkilpa]

Personally, I recommend you always pull the entire drive when working on it. Then during reassembly you can drop the upper down onto the lower, which is much much easier than trying to lift the lower up without kicking it out of forward gear or damaging the seals.

This is good advice I will take in the future. No more removing just the lower half for me...

Funny story:

I didn't have any lube leaks when I put everything back together. However, when I returned to my vacation house a couple of months later, there was a good size puddle of lube under the drive. I was hoping that it was something simple like the quad ring not seated properly, but I wasn't going to tackle it myself with the difficulty I had putting the 2 halves together from the bottom-up without a drive stand.

Took it in for a pressure test and it turns out I damaged the vertical shaft seal when I was poking the drive shaft into the top trying to line things up. Also, the shift shaft seal was leaking too.

So, in my attempt to save $250 by doing the impeller replacement myself, I spent an additional $400 to have my drive sealed properly. Oh well....it's like spending just $150 more than I would have had I just had the shop do it in the first place.

But the purpose of this post is to answer the question I posed originally. The water tube guide sleeve was not in the exhaust passage when it was inspected, so it was never there to begin with. At least I was able to give the shop the sleeve I purchased and it is in place now.

I will build a stand that will allow me to remove the whole drive and service it properly next time.